Yuval Levin dusts off his history books and offers National Review Online readers an anecdote that should inform a current controversy.

In an interview with the New York Post on Wednesday, President Trump took up the possibility of offering a pardon to his former campaign chairman Paul Manafort. …

“It was never discussed, but I wouldn’t take it off the table. Why would I take it off the table?” the president said during an Oval Office interview.

Two great Virginians could tell him why. The pardon power was a subject of real concern in some of the debates over the ratification of the Constitution. At the Virginia ratifying convention, in June of 1788, it was raised by no less an eminence than George Mason. His particular worry was that a president might use that power to protect himself from investigation or prosecution. “Now, I conceive that the President ought not to have the power of pardoning because he may frequently pardon crimes which were advised by himself,” Mason said. “If he has the power of granting pardons before indictment, or conviction, may he not stop inquiry and prevent detection?”

James Madison himself rose up to answer the argument, saying it was a very serious point but that a president’s doing such a thing would be an obvious ground for impeachment. …

… The open-ended nature of the pardon power means that impeachment is really the only remedy for a serious abuse of that power.